System for producing a one-piece orthodontic jig and attachments

ABSTRACT

A method for producing a one-piece orthodontic jig and attachments employs a computer-aided design (CAD) system to create a model of a patient&#39;s dental anatomy. A set of orthodontic attachments and their desired positions are also designed in the CAD model. An orthodontic jig for temporarily positioning the attachments during the bonding process is then designed that includes features for registering the jig to selected teeth, together with connecting members that detachably connect the attachments to the jig and hold the attachments in their desired position on the patient&#39;s teeth during the bonding process. The orthodontic jig and attachments is fabricated as a single piece by computer-controlled manufacturing (e.g., 3D printing) based on the CAD model.

RELATED APPLICATION

The present application is based on and claims priority to theApplicant's U.S. Provisional patent application Ser. No. 14/726,794,entitled “System for Producing a One-Piece Orthodontic Jig andBrackets,” filed on Jun. 1, 2015.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates generally to the field of orthodontics.More specifically, the present invention discloses an automated systemfor producing a one-piece orthodontic jig and attachments from a CADmodel using computer-controlled manufacturing techniques, such as 3Dprinting.

Statement of the Problem

Orthodontics is the practice of straightening teeth and the harmonizingof the dental occlusion. The orthodontic process typically involves adiagnosis of the patient's pre-treatment dental and occlusal conditions,the development of a treatment plan, and the utilization of medicaldevices, such as orthodontic braces, to achieve the desired treatmentoutcome.

Precise bracket positioning, predictable biomechanics, and aestheticsare three orthodontic device performance dimensions that are thought tobe critical for achieving efficient and effective treatment outcomes andsatisfactory patient experiences. Precise bracket positioning involvesplacing the brackets on the teeth relative to anatomical landmarks, suchas the incisal edge of the teeth, in accordance with the desiredprescription. Predictable biomechanics are governed by the ability ofthe orthodontic bracket to faithfully deliver to the teeth the torque,tip, rotation, in/out, extrusion/intrusion and sliding mechanicsmovements specified by the prescription. Aesthetics are typicallydefined as the extent to which the orthodontic devices are invisible andthe appliances match the natural shade of the patient's teeth duringtreatment. Though orthodontists routinely achieve acceptable treatmentresults with the existing landscape of orthodontic devices, limitationsexist. Limitations exist with respect to these three key performancedimensions.

Precise bracket positioning relative to the desired prescription isoften beyond the human capability. Placement errors of even a fractionof a millimeter can result in unintended and unpredictable toothmovements. These erroneous tooth movements can lead to unplannedinterventions, compensating adjustments, additional appointments,extended treatment times and iatrogenic side effects.

The conventional techniques currently used in orthodontics includedirect bonding, in which the practitioner manually positions eachbracket on a tooth during the bonding process; and indirect bonding,which uses a bonding tray or placement jig to position a set of bracketson the teeth during bonding. A wide variety of orthodontic bonding traysand placement jigs are commercially available from a number of sources,including Ormco, 3M Unitek, Orapix, American Orthodontics andOrthoselect.

The prior art in this field also includes the following:

U.S. Pat. No. 8,734,149 (Phan et al.) and U.S. Pat. No. 7,658,610(Knopp) disclose examples of CAD/CAM systems for producing a dentaltemplate for etching or for positioning brackets on teeth. However, thebrackets are separate objects that must be subsequently placed into thetemplate.

U.S. Pat. Nos. 5,368,478, 5,447,432, 5,454,717 and 5,431,562 (Andreikoet al.) disclose CAD/CAM systems for designing and producing many of thecomponents for conventional orthodontic treatment (i.e., brackets,wires, and jigs), but not as a single piece.

U.S. Pat. Nos. 8,060,236, 7,950,131 and 7,077,646, and U.S. Patent App.Pub. No. 2008/0254403 (Hilliard) disclose examples of CAD/CAM systemsfor producing orthodontic components, such as orthodontic aligners andarchwires.

U.S. Pat. No. 7,234,934 (Rosenberg) discloses a computer-configuredorthodontic appliance that incorporates a set of prong units forattachment to selected teeth. A progressive series ofcomputer-configured segmented compartment arches can then be snappedonto the prong units.

It should be noted that all of the above references that employorthodontic brackets either: (1) require a manual step in positioningthe brackets on the teeth, which is time-consuming, subject to errors inbracket order, and inherently introduces a degree of inaccuracy in theposition of the brackets on the teeth; or (2) require the user tomanually place individual brackets in the correct order into a templateor bonding tray, which is also time-consuming and subject to errors inbracket order. In contrast, the present invention is designed toovercome these limitations by providing an automated system thatproduces an orthodontic jig and brackets as a one-piece directly from aCAD model using computer-controlled manufacturing techniques to addressthese shortcomings in the prior art.

SUMMARY OF THE INVENTION

This invention provides an automated system for producing a one-pieceorthodontic jig and brackets by computer-controlled manufacturing. Acomputer-aided design (CAD) system is employed to create a model of apatient's dental anatomy, and a set of orthodontic brackets and theirdesired positions are also designed in the CAD model. An orthodontic jigfor temporarily positioning the brackets during the bonding process isthen designed that includes features for registering the jig to selectedteeth, together with connecting members that detachably connect thebrackets to the jig and hold the brackets in their desired position onthe patient's teeth during the bonding process. The orthodontic jig andbrackets is fabricated as a single piece by computer-controlledmanufacturing (e.g., 3D printing) based on the CAD model.

These and other advantages, features, and objects of the presentinvention will be more readily understood in view of the followingdetailed description and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be more readily understood in conjunction withthe accompanying drawings, in which:

FIG. 1 is a top axonometric view of an example of an orthodontic jig andbrackets produced using the present system.

FIG. 2 is a bottom axonometric view of an orthodontic jig and bracketscorresponding to FIG. 1.

FIG. 3 is a block diagram of the present system.

FIG. 4 is a flowchart of the present methodology.

FIG. 5 is a rear axonometric view of a CAD model of a patient's dentalanatomy showing the desired placement of orthodontic brackets in dottedlines.

FIG. 6 is an axonometric view of a bracket with a curved archwire slot26.

FIG. 7 is a top view of an orthodontic jig 20 and brackets 25 in placeon a patient's teeth 10.

FIG. 8 is a top view similar to FIG. 6 in which a pre-loaded archwire 80has been added to the brackets 25.

FIG. 9 is a top view of an orthodontic jig 20 and other types oforthodontic attachments 50-53 on a patient's teeth 10.

FIG. 10 is a cross-sectional view of the orthodontic jig 20 withorthodontic attachment 53 on a tooth 10.

DETAILED DESCRIPTION OF THE INVENTION

Turning to FIG. 1, an example is provided of a one-piece orthodontic jig20 and brackets 25 produced using the present system. FIG. 2 is acorresponding bottom axonometric view. The device includes apatient-specific bracket-positioning jig 20 that typically spansmultiple teeth and directly connects to the brackets 25 via acorresponding set of connecting members 22 for the purpose of precisebracket positioning during the bonding process. For example, the bracketlocations can be determined from a therapeutic model or a prescription.

Unlike current direct and indirect bracket positioning methods thatrequire the manual step of placing brackets on teeth or on a transfermodel for indirect bonding, the present invention is a one-piece systemthat can be directly manufactured from a patient-specific CAD modelusing computer-controlled manufacturing techniques, such as 3D printing.Alternatively, the present invention can be used to produce a one-piecemodel (e.g., a wax or polymer model) by 3D printing that is subsequentlyused to form a mold for casting the final appliance in a more suitablematerial, such as metal. The present invention could also be used todirectly create a mold for casting the final appliance.

After the appliance has been manufactured, the bracket-positioning jig20 can be used to precisely position the brackets 25 during the bondingprocess. In other words, the bracket-positioning jig 20 is designed todirectly and precisely transfer the prescribed bracket positioningdesigned in the CAD system into the actual bracket positioning on apatient's teeth. The connecting members 22 between thebracket-positioning jig 20 and the brackets 25 are designed to be easilydetached from the brackets 25 after bonding. The advantage of theone-piece construction is the direct, mechanical transfer of theprescription that eliminates the manual placement of each bracket oneach tooth, or transfer model for indirect bonding.

The present device is designed to be utilized across a variety ofmanufacturing materials as well as common orthodontic bracket designmodalities such as slot size and shape, ligation method and bracketdesign. The components of the present device can be fabricated using awide range of materials not limited to plastic, metal alloys andceramics such as zirconia for the purpose of enhancing aesthetics. Forexample, shaded ceramic and plastic materials allow the device to blendin with the natural color of the patient's teeth.

In the embodiment shown in FIGS. 1 and 2, the bracket-positioning jig 20is a thin planar member that is curved to generally follow the arch formof a patient's upper or lower dental arch. However, the jig 20 couldhave other configurations. Here, the jig 20 is designed to rest on theocclusal surfaces of the patient's teeth.

A customized jig mating surface 21 can be formed on the jig 20 at theinterface between the occlusal surfaces of the patient's teeth and thejig 20. This jig mating surface 21 can be customized in the CAD processto the teeth of the patient as a direct negative of the occlusal anatomyof the patient's teeth. This creates a positive, unique andtooth-specific match between the occlusal surfaces of the patient'steeth and the jig 20 to help ensure accurate registration of the jig 20and brackets 25 with respect to the teeth. In turn, this creates areference point that allows the bracket-positioning prescription to bedirectly transferred into the positioning of the remaining components ofthe present device. More generally, other types of features, such asrecesses or protrusions, can be included in the design of the jig 20 tohelp ensure registration of the jig 20 on the patient's teeth during thebonding process.

The present device also includes a series of orthodontic brackets 25that feature archwire slots to receive a conventional orthodonticarchwire during treatment of the patients. The brackets 25 can becustomized during the CAD process to meet specific patient needs andrequirements. Each bracket 25 typically includes an archwire slot 26extending a generally mesial-distal direction, as shown in FIG. 6, thatreceives and interacts with an archwire during subsequent orthodontictreatment. The cross-sectional shape of the archwire slot 26 may beround, rectangular, square, or other shapes. The brackets 25 can bedesigned to be placed on the lingual or labial surfaces of the patient'steeth.

Optionally, the brackets 25 can include a patient-specific curvedarchwire slot 26. FIG. 6 is a front axonometric view of a bracket 25with a curved archwire slot 26. The curvature, or radius, of thearchwire slot 26 can be designed to match the desired arch formprescribed for the patient for the purpose of enhancing the precisionand predictability of tooth movement during treatment. For example, thecurvature (or radius) of the archwire slot 26 may be based on the archform prescription for the patient, or a standard preference arch form,or a radius established by the prescribing orthodontist or dentist.Alternatively, the archwire slot 26 can be straight. The archwire slot26 may also feature a tube-shaped design with enclosures on all sides,or the archwire slot 26 may feature an open slot design with an openside in one dimension, such as the facial or occlusal dimension.

Optionally, the brackets 25 can be equipped with upper or lowerauxiliary slots 27, 28 (shown in FIG. 6) to enable the orthodontist toligate, or hold, an archwire into the archwire slot 25. Placed on theincisal portion of the bracket body relative to the archwire slot 25,the auxiliary slots 27, 28 can also be used as a secondary archwireslot. The auxiliary slots 27, 28 also create a purchase point for theutilization of elastomeric or metal ligatures, power chains, or otherauxiliary attachments. The auxiliary slots 27, 28 may be linear orradiused based on the desired arch form for the patient.

Each bracket 25 can also include a custom pad 29 as the interfacebetween the lingual or labial surface of the patient's teeth and thebracket body. The orthodontist typically bonds the bracket to the teethby applying bonding agents to the pad 29. The mating surface of the pad29 can be customized during the CAD process to be a direct negative ofthe dental anatomy of the patient's teeth. The result is a positive,unique, and tooth-specific match between the mating surface of the pad29 and the labial or lingual surface of the patient's teeth.

Optionally, the brackets 25 can also be equipped with rebonding jig armsthat extend from the bracket 25 to allow the orthodontist to preciselyposition the brackets in the event that the bracket needs to be rebondedor bonded later in treatment. The rebonding jig arms can be customizedto match the dental anatomy of each tooth, allowing for accurate bracketpositioning.

To summarize, the brackets 25 can be designed during the CAD process inany number of configurations and for multiple ligation methodsincluding, but not limited to metal ligatures, elastomeric ligatures, orself-ligating mechanisms. The present invention is designed for variousbracket body, bracket base and tiewing designs including but not limitedto twin, edgewise, single wing, Lewis wing, torque in face, torque inbase and other designs.

The connecting members 22 are the attachment mechanisms extending fromthe bracket-positioning jig 20 to each bracket 26. The connectingmembers 22 are designed to transfer the bracket-positioning prescriptionfor each bracket 25 from the positioning jig 20 to the brackets 25during the bonding process. After the brackets 25 are bonding, theconnecting members 22 are cut, released or detached from the brackets 25to allow for the removal of the jig 20 after bonding has been completed.

Optionally, a preloaded archwire 80 can be placed into the archwireslots 26 of the brackets 25 (as shown for example in FIG. 8) before thepresent device is introduced to the patient. The preloaded archwire 80can be embedded during the fabrication process or inserted at a latertime. Preloading the archwire 80 is thought to improve chair time. Thearchwire 80 can have any of a variety of cross-sectional shapes,including but not limited to round or rectangular; and can be made ofany of a variety of materials, including but not limited to nitinol andstainless steel. In this embodiment, the connecting members 22 should bedesigned with sufficient rigidity to withstand the deflection force of apreloaded archwire 80.

FIG. 3 is a block diagram of an embodiment of the system used to designand fabricate the one-piece orthodontic jig 20 and brackets 25 describedabove. FIG. 4 is a corresponding flowchart of the steps involved. Instep 40, a model 34 of the patient's dental anatomy is initially createdusing CAD software 33 operating on a conventional computer system 32.For example, the CAD model 34 can be created by optical scanning of thepatient's dental anatomy using a scanner 30, as shown in FIG. 3. A scanof conventional stone models of the patient's dental anatomy or dentalx-ray imaging could also be employed.

After a CAD model 34 of the patient's dental anatomy has been created,the CAD software 33 can be used by the operator to design a set oforthodontic brackets 25 for treatment of the patient (step 41 in FIG.4). This typically includes choosing the desired positions of thebrackets 25 on selected teeth in the CAD model in accordance withorthodontic practices. As shown for example in FIG. 5, the CAD software33 enables the operator to interactively view the patient's dentalanatomy 15 while designing the placement of the virtual brackets 25.Here, the intended positions of the virtual brackets 25 are illustratedin dotted lines.

In step 42 of FIG. 4, the user continues the design process by creatinga CAD model 36 of an orthodontic jig 20 for temporarily positioning thebrackets 25 during the bonding process to selected teeth. This jig 20includes features 21 (e.g., customized mating surfaces) for registeringthe jig 20 to selected teeth, and also includes connecting members 22removably connecting the brackets 25 to the jig 20. The connectingmembers 22 are designed to hold the brackets in their desired positionson the patient's teeth during the subsequent bonding process. Theorthodontic jig 20, brackets 25 and connecting members 22 are designedas a single piece, as previously discussed.

In step 43 of FIG. 4, the CAD model 36 of the orthodontic jig 20 andbrackets 25 is used by computer-aided manufacturing (CAM) software 35 togenerate a set of instructions to control operation of acomputer-controlled manufacturing device 38 to produce the orthodonticjig and brackets as a single piece. For example, the appliance can beprinted from a suitable polymeric material using a 3D printer, or formedfrom a blank of a suitable material by CNC milling or machining.

After the appliance has been fabricated, it can be placed on thepatient's teeth 10, in step 44 of FIG. 4. FIG. 7 is a top view of anexample of an orthodontic jig 20 and brackets 25 in place on a patient'steeth 10. The registration features 21 of the orthodontic jig 20 helpensure accurate registration with the teeth 10. In step 45, the brackets25 are bonded to the patient's teeth 10 with the jig 20 and connectingmembers 22 providing accurate positioning of the brackets 25 withrespect to the teeth 10. Finally, the connecting members 22 are detachedfrom the brackets 25 (step 46) and the orthodontic jig 20 is removed(step 47), while leaving the brackets 25 attached to the patient's teeth10. For example, the connecting members 22 can be removed by cuttingthem with small wire cutting pliers or scissors.

The present invention can also be used to create a bonding system forother types of orthodontic attachments, in addition to brackets. FIG. 9show various types of lingual orthodontic attachments 50-53. Theseattachments can be placed labially or lingually depending on thetreatment plan. For example, this delivery system accurately placesorthodontic attachments 50-53 to engage any of a wide variety ofremovable orthodontic appliances to create secondary or tertiaryorthodontic tooth movement. FIG. 10 shows the cross-section of anorthodontic attachment 53 that has been accurately placed on a tooth 10by the attachment jig 20. Such orthodontic attachments 50-53 can be usedto engage archwires with round or rectangular cross-sections. Inaddition, many types of conventional orthodontic appliances can belocked into, on top of, or below the attachment 50-53 (e.g., appliancesto expand teeth such as a quad helix expander, transpalatal bar, Hyrax,lip bumper, Blue Grass appliance, distal jet, Inman-style powercomponent, Hawley-style retainer, etc.).

The above disclosure sets forth a number of embodiments of the presentinvention described in detail with respect to the accompanying drawings.Those skilled in this art will appreciate that various changes,modifications, other structural arrangements, and other embodimentscould be practiced under the teachings of the present invention withoutdeparting from the scope of this invention as set forth in the followingclaims.

We claim:
 1. A method for producing a one-piece orthodontic jig andattachments comprising: creating a model of a patient's dental anatomyin a computer-aided design (CAD) system; designing in the CAD model aset of orthodontic attachments for treatment of the patient, includingthe desired positions of the attachments on selected teeth in the CADmodel; designing in the CAD model an orthodontic jig as a single piecewith the attachments for temporarily positioning the attachments duringa bonding process to selected teeth, said jig including features forregistering the jig to selected teeth, and further including connectingmembers having thin, elongated members connecting the attachments to thejig designed to hold the attachments in their desired position on thepatient's teeth during the bonding process; and producing an orthodonticjig and attachments as a single piece by computer-controlledmanufacturing based on the CAD model.
 2. The method of claim 1 whereinthe orthodontic jig and attachments are produced by three-dimensionalprinting.
 3. The method of claim 1 wherein the orthodontic jig andattachments are produced by computer numerical control (CNC) machining.4. The method of claim 1 wherein the orthodontic jig and attachments areproduced by computer numerical control (CNC) milling.
 5. The method ofclaim 1 wherein the orthodontic jig includes features to register theorthodontic jig to the occlusal surfaces of selected teeth.
 6. A methodof orthodontic treatment comprising: creating a model of a patient'sdental anatomy in a computer-aided design (CAD) system; designing in theCAD model a set of orthodontic attachments for treatment of the patient,including the desired positions of the attachments on selected teeth inthe CAD model; designing in the CAD model an orthodontic jig as a singlepiece with the attachments for temporarily positioning the attachmentsduring a bonding process to selected teeth, said jig including featuresfor registering the jig to selected teeth, and further includingconnecting members having thin, elongated members connecting theattachments to the jig designed to hold the attachments in their desiredposition on the patient's teeth during the bonding process; producing anorthodontic jig and attachments as a single piece by computer-controlledmanufacturing based on the CAD model; placing the orthodontic jig andattachments on the patient's teeth using the registering features;bonding the attachments to the patient's teeth with the jig andconnecting members providing accurate positioning of the attachmentswith respect to the patient's teeth; and cutting the thin, elongatedmembers to detach the attachments and removing the jig from thepatient's teeth.
 7. The method of claim 6 wherein the orthodontic jigand attachments are produced by three-dimensional printing.
 8. Themethod of claim 6 wherein the orthodontic jig and attachments areproduced by computer numerical control (CNC) machining.
 9. The method ofclaim 6 wherein the orthodontic jig and attachments are produced bycomputer numerical control (CNC) milling.
 10. The method of claim 6wherein the orthodontic jig includes features to register theorthodontic jig to the occlusal surfaces of selected teeth.
 11. Aone-piece orthodontic jig and attachments made by a process comprisingthe steps of: creating a model of a patient's dental anatomy in acomputer-aided design (CAD) system; designing in the CAD model a set oforthodontic attachments for treatment of the patient, including thedesired positions of the attachments on selected teeth in the CAD model;designing in the CAD model an orthodontic jig as a single piece with theattachments for temporarily positioning the attachments during a bondingprocess to selected teeth, said jig including features for registeringthe jig to selected teeth, and further including connecting membershaving thin, elongated members connecting the attachments to the jigdesigned to hold the attachments in their desired position on thepatient's teeth during the bonding process; and producing an orthodonticjig and attachments as a single piece by computer-controlledmanufacturing based on the CAD model.